Snowmobile trail groomer

ABSTRACT

A grooming apparatus for snow surfaces such as snowmobile trails comprises a heavy elongate frame having an articulated forward end supported on skis, and a rear end supported on a skid. Centrally of the frame is a transverse blade structure behind which is positioned a massive pivotally mounted compactor bar. In contrast to new equipment of this type, the present grooming apparatus provides for vertical adjustment of the frame relative to the front skis and the rear skid.

United States Patent 1 Boisse et a1.

[4 1 Apr. 22, 1975 1 1 SNOWMOBILE TRAIL GROOMER [75] Inventors: PierrePaul Boisse; Jacques Bombardier; Rejean Leclerc, all of Valcourt.Quebec. Canada [73] Assignee: Bombardier Limited, Valcourt,

Quebec, Canada [22] Filed: Oct. 17, 1973 [21] Appl. No.: 407,154

[30] Foreign Application Priority Data Nov. 16, 1972 Canada 156658 [52]US. Cl. 172/145; 172/188, 172/197; 172/407; 172/784; 37/50 [51] llnt. ClA01b 51/00 [58] Field of Search 172/145. 133. 140, 188. 172/197, 199,387, 392. 393, 395,407, 413,

[56] References Cited UNITED STATES PATENTS 243,261 6/1881 Hove) 37/481.796.166 3/1931 Sharpm. 172/780 X 2,635,888 4/1953 Bailiff 172/413 X2,681,519 6/1954 Potter 172/780 2.786.283 3/1957 Bradley" 37/102,880,528 4/1959 Lusk 172/780 X 3.043.034 7/1962 Kobcr.... 172/780 X3,091,476 5/1963 Blake..... 172/413 X 3,237,324 3/1966 Eddins r 172/7803,490,541 1/1970 Adams, Jr 172/116 3.755930 9/1973 Brandt et a1. 37/41 XFORElGN PATENTS O'R APPLlCATlONS 773.163 4/1957 United Kingdom 37/50Primary E.vaminerEdgar S. Burr Assistant E.\'uminerE. H. Eickholt [5 7]ABSTRACT A grooming apparatus for snow surfaces such as snowmobiletrails comprises a heavy elongate frame having an articulated forwardend supported on skis, and a rear end supported on a skid. Centrally ofthe frame is a transverse blade structure behind which is positioned amassive pivotally mounted compactor bar. In contrast to new equipment ofthis type. the present grooming apparatus provides. for verticaladjustment of the frame relative to the front skis and the rear skid.

13 Claims, 4 Drawing Figures SNOWMOBILE TRAIL GROOMER FIELD OF THEINVENTION This invention relates to apparatus for conditioning orgrooming snow surfaces for winter sports activities. for examplesurfaces such as ski slopes or snowmobile trails.

BACKGROUND OF THE INVENTION Existing equipment for the grooming ofsnowmobile trails generally comprises light and fairly short frameswhich are dragged across the snow surface by snowmobiles and carry ontheir undersides one or more chopping blades. Such devices. being fairlylight. can only chop off the tops of any moguls which may be present inthe snow surface. and accordingly on a snow surface having large mogulsnumerous passes of such devices are required to achieve adequategrooming of the surface.

SUMMARY OF THE INVENTION The present invention provides apparatus forgrooming a snow surface comprising: an elongate frame having forward andrearward ends and skid means adjacent each end to support the frame forsliding movement upon the snow surface. a blade structure carried bysaid frame and extending transversely thereof. said blade structurehaving a generally horizontal lower edge. a horizontal compactorextending transversely of the frame and mounted thereon rearwardly ofthe blade structure. and means for adjusting the height of said framerelative to said skid means.

Preferably at least the lateral ends of the blade structure are angledfonvardly so as to guide snow chopped from the snow surface towards thelongitudinal center line of the frame. A transverse deflector plate maybe provided. above and to the rear of the blade structure to direct snowfrom the blade structure downwards into the path of the compactor.

In a preferred embodiment the grooming apparatus comprises a large.heavy frame supported at the front upon a pair of skis and at the rearupon a skid plate and adjustable in height relative to the skis and skidplate so that the vertical position of the blade structure can bevaried. The front skis are mounted on a hitch which is articulated withrespect to the remainder of the frame to improve the steeringcharacteristics of the apparatus. The compactor comprises a massivesolid steel bar transversely arranged to the rear of the blade structureand pivotally supported from the frame by a trailing arm structure. Thedimensions of the apparatus are relatively large. for example 30 ft.long and ft. wide. so that the position of the blade structure isrelatively insensitive to local variations in the contour of the snowsurface.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will further bedescribed. by way of example only with reference to the accompanyingdrawings in which:

FIG. 1 is a side elevation. and

FIG. 2 is a plan viewof a preferred embodiment of snow groomingapparatus in accordance with the invention;

FIG. 3 is a front perspective view of the apparatus from above and oneside; and

FIG. 4 is a rear perspective view from above and the other side showingthe rear portions of the apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings. thesnow grooming apparatus comprises a frame having a forward hitch sectionII and a major rear section 12.

As is best seen in FIG. 4. the rear section 12 of the frame comprises amassive hollow steel beam 13 transversely arranged between a pair ofspaced lateral frame members I4 and secured thereto by any suitablemeans. e.g. by welding. Connected to the front end of each of thelateral frame members 14 is an angularly arranged frame member 15. thelatter converging towards the front of the rear frame section and beingconnected together and to a clevis plate 16. e.g. by welding. A centralframe member I7 extends longitudinally in the rear frame section and isconnected at its forward end to the clevis plate I6. and at its rear endto the transverse beam I3.

About two-thirds of the way between the front and rear of the frame 10.a blade structure generally indicated at 18 is mounted on the rear framesection 12. As is best seen in FIG. 3. the blade structure comprisesvertical end brackets 19 secured to the undersides of the lateral framemembers 14. and a central bracket 20 secured to the underside of thecentral frame member 17. The lower ends of the brackets 19 and 20incline downwardly and forwardly of the frame and support cutting bladesections 21 on each side of the central bracket. The cutting bladesections 21 are of rigid construction being fabricated for example in asuitable hardened steel. and have serrated lower cutting edges 22 andwhich extend in a generally horizontal plane. i.e. a plane parallel tothat of the frame members l4. l5 and 17. Conveniently the cutting bladesections 21 may be detachably secured to the support brackets I9 and 20so that they may be removed and replaced should they become defectivethrough breakage or wear.

The cutting blade sections lie at an angle to the horizontal ofapproximately 45. and the central support bracket 20 is positionedsomewhat rearwardly of the end brackets 19 so that in plan view. thecutting blade sections appear in the form of a shallow V. the laterallyoutermost sections being inclined forwardly with respect to the centralparts.

A snow deflector plate 25 is mounted on the rear frame section 12 aboveand to the rear of the blade structure 18. From each of the lateralframe members 14 extends a pair of vertical lugs 26 and 27 to which thelateral ends of the deflector plate 25 are connected. It will be seemthat the forwardmost lugs 26 are of greater height than the lugs 27 sothat the deflector plate is supported at a downwards inclination towardsthe rear.

A snow compactor 28 is mounted on the rear frame section behind theblade structure and snow deflector.

As is best seen in FIG. 4 the compactor comprises a horizontallyarranged massive steel bar 29 supported through trailing arms 30 and 31on the structure of the rear frame section. The trailing arms 30 at theouter ends of the compactor bar are connected to co-axial pivotalmountings 32 on the lateral frame members I4, whereas the centraltrailing arm 31, which comprises a pair of spaced plates 33 whichstraddle the central frame member 17, is connected to a pivotal mounting34 carried on the central frame member and co-axial with the pivotalmounting 32. Thus the compactor bar 29 is free to swing about thepivotal axis of the mountings 32 and 34. the pivotal movement in thedownward direction being limited by engagement of the central trailingarm 32 with an abutment plate 35 mounted on thecentral frame member 17.The abutment plate 35 therefore defines a limiting position for thecompactor bar. and in this position. as seen in FIG. 1. the compactorbar is at the same horizontal level as the cutting edges 22 of the bladestructure.

At the rear of the frame section 12 is a skid support 36 in the form ofa transversely arranged horizontal tube 37 pivotally mounted at oppositeends in bearing supports 38 at the rear of the lateral frame members 14.and centrally in a bearing support 39 carried on the rear of the centralframe member 17. A pair of radial arms 40 are integrally connected withthe tube 37 near the ends thereof. and the lower end of each arm 40 ispivoted on a pin 41 supported between vertical mount ing plates 42secured at transversely spaced locations to the upper surface of a skidplate 43. The skid plate 43 extends the full width of the rear framesection 12 andfhas an upwardly curved front end.

Centrally of the tube 37 is a third radial arm 44 in the form of twoplates 45 integrally connected to the tube 37 on opposite sides of thecentral bearing support 39. The upper end of the arm 44 is pivotallyconnected by means of a pin 46 to the end of a piston rod 47 of ahydraulic piston and cylinder assembly 48. The opposite end of thepiston and cylinder assembly 48 is pivotally connected to a bracket 49on the central frame member l7 through a pin 50. The piston and cylinderassembly 48 can be supplied with hydraulic fluid through hoses 51 toeffect extension and retraction of the piston rod 47. As will beevident. movement of the piston rod 47 imparts a pivotal motion to thetube 37 and with it the arms 40 carrying the skid plate 43. As will beclear from H6. 1. actuation of the piston and cylinder assembly 48 willvary the effective height between the skid plate 43 and the framesection 12. but the skid plate will be able to maintain a generallyhorizontal position during this movement because of its pivotalconnection with the arms 40.

As is best shown in FIGS. 2 and 3, the forward hitch section llof theframe is of generally triangular configuration and comprises atransverse rear frame member 52 of hollow steel beam structure. from theends of which a pair of lateral frame members 53 extend forwardly inconvergent fashion to an apex 54 at which is provided a hitch connection55 for attachment to a tractor vehicle (not shown).

The forward frame section 11 is of massive integral construction. theframe members preferably being hollow steel beams interconnected bywelding. At each end of the rear frame member 52 is a downwardlyextending post 56 rigidly attached thereto. Welded gusset plates 57 areprovided to strengthen the connections between the frame members 52 and53 and the posts 56. and a lower transverse beam 58 is connected between the posts 56. The lower end of each post is pivotally connectedthrough a transverse pin 59 to a mounting bracket 60 on the upper sideof a front ski 61. the skis 61 thus being capable of pivoting withrespect to the forward frame section 11.

A hydraulic piston and cylinder assembly 62 is vertically-arranged onand centrally attached to the rear frame member 52 and the lower beam58, with the piston rod 63 extending upwardly therefrom.

The upper end of the piston rod is attached to a flange 64 carried by avertically arranged plate 65 slidably received in a T shaped channel 66ofa guide block 67 mounted on the rear of the forward frame section. Theplate 64 is thus guided for vertical movement in the channel 66 uponextension or retraction of the piston rod 63.

Attached to the rear face of the plate 65 is a bracket 68 which receivesthe clevis plate 16 of the rear frame section 12. A pin 69 receivedthrough aligned holes in bracket 68 and clevis plate 16 forms a pivotalconnection between two frame sections allowing relative articulatingmotion therebetween about a vertical axis.

The piston and cylinder assembly 62 is supplied with hydraulic fluidthrough hoses 70 which are conducted to the forward end of the frontframe section along the rear and lateral frame members 52 and 53. Thehoses 51 supplying the piston and cylinder assembly 48 are conductedalong the central frame member 17 of the rear section. and along therear and lateral frame members of the front frame section so that bothsets of hoses terminate adjacent the hitch connection 55 and may readilybe coupled to a source of hydraulic cluid on the tractor vehicle (notshown).

In operation. when the apparatus is drawn over a snow surface to begroomed. for example. a snowmobile t'rail. the cutting edge 22 of theblade structure moves in a direction substantially parallel to that ofthe snow surface. irrespective of minor irregularities in that surface.This is because the blade structure is attached to the massive rearframe section 12. and the latter is retained in a generally horizontalposition because of the wide track of the skis 61, and the largedistance be tween the front skis 6] andthe rear skid plate 43.Accordingly the grooming apparatus is most effective in levelling mogulswhich may occur on the snow surface. In operation, when the cutting edge22 encounters a mogul it slices the top from it. the snow or ice thusloosened passing up over the inclined surfaces of the blade sectionsbeing directed generally inwardly of the track of the skis by virtue ofthe shallow V shaped arrangement of the blade sections.

The compactor 28 drags behind the cutting blade. and the heavy steel bar29 is effective to compact snow severed by the cutting blade sectionsinto any hollows which may exist in the snow surface.

The snow deflector plate 25 is effective to direct the snow severed bythe cutting blade sections downwardly into the path of the compactor 28.By virtue of its pivotal mounting arrangement. the compactor 28,although normally effective to compact the severed snow. may swingupwardly and rearwardly to permit it to clear any large obstacle whichmay be encountered.

At the rear end of the grooming apparatus the rear skid 43 slidesaccross the compacted snow surface and effects a further compacting andgrooming action.

Dependent upon the condition of the snow surface to be groomed. and thehardness of the snow. it may be desirable to vary the height of thecutting edges 22 of the blade structure in relation to the skis 61 andskid plate 43. This may be effected through actuation of the hydrauliccylinder 48 to pivot the ski support structure 36 to move the rear skidplate to the desired height. and by actuation of the cylinder 62 toadjust the height of the plate 65. and with it the front clevis 16 ofthe rear frame section in relation to the front skis 61.

The articulated connection between the front frame section 11 and therear frame section 12 provides the apparatus with high maneuverabilitydespite its extended length.

What we claim as our invention is:

1. Apparatus for grooming a snow surface comprising an elongate framehaving forward and rearward ends and skid means adjacent each end tosupport the frame for sliding movement upon the snow surface. a bladestructure carried by said frame and extending transversely thereof. saidblade structure having a generally horizontal lower edge. a horizontalcompactor extending transversely of the frame and mounted thereonrearwardly of the blade structure. said compactor com prising a heavy.rigid. elongate member pivotally mounted on an axis transverse to saidframe. abutment means on said frame defining a limiting position forsaid compactor. said limiting position being spaced rearwardly anddownwardly of the pivotal axis such that the compactor is urged bygravity towards said lim iting position but in operation may bedisplaced pivotally upwardly and rearwardly by the mass of snow to becompacted. and means for adjusting the height of said frame relative tosaid skid means.

2. Apparatus for grooming a snow surface comprising an elongate framehaving forward and rearward ends and skid means adjacent each end tosupport the frame for sliding movement upon the snow surface. a bladestructure carried by said frame and extending transversely thereof. saidblade structure having a generally horizontal lower edge. a horizontalcompactor extending transversely of the frame and mounted thereonrearwardly of the blade structure. a deflector plate mounted on saidframe above and adjacent the rear of said blade structure. saiddeflector plate being of a length corresponding to that of the bladestructure and being downwardly inclined in the rearward direction sothat in operation it acts to deflect snow shaved by the blade structuredownwards into the path of the compactor, and means for adjusting theheight of said frame relative to said skid means.

3. Apparatus according to claim 2 wherein the blade structure isdownwardly and forwardly inclined at an angle of approximately 45 to thevertical.

4. Apparatus according to claim 2 wherein said front skid meanscomprises a pair of spaced skis on the front portion of the frameadjacent the lateral edges thereof the rear skid means comprising aplate which extends the full width of the frame.

5. Apparatus according to claim 2 wherein said blade structure and saidcompactor extend over substantially the full width of the frame.

6. Apparatus according to claim 2 further comprising a support pivotallymounted on a transverse axis at the rear of said frame said supportcarrying a pair of spaced. downwardly extending arms and the lower endof each arm being pivoted to the rear skid means. and actuator means onsaid frame operative to pivot said support relative to said framethereby to adjust the ef fective height of said frame relative to saidrear skid means.

7. Apparatus according to claim 6 wherein said actuator means comprisesa fluid pressure operated piston and cylinder assembly connected at oneend to said frame and at its opposite end of said support at a locationspaced from the pivotal axis of the latter.

8. Apparatus according to claim 6 wherein said frame has a forwardsection upon which said front pair of skis is mounted and which isarticulated with respect to the remainder of said frame upon which saidblade and said compactor are mounted. said forward section of the framebeing adjustable in the vertical direction with re spect to theremainder of said frame thereby to vary the effective height of thelatter with respect to the front skid means.

9. Apparatus according to claim 8 wherein said vertical adjustment iseffected through a fluid pressure operated piston and cylinder assemblyconnected between the forward section of said frame and the remainder ofthe frame.

10. Apparatus according to claim 2 wherein at least the lateral endportions of said blade structure are forwardly inclined with respect tosaid transverse direction.

11. Apparatus according to claim 2 wherein said blade structurecomprises two blade sections which meet centrally of the frame andextend laterally therefrom at a slight forward inclination.

12. Apparatus according to claim 5 wherein the front skid meanscomprises a pair of spaced skis on the front portion of the frameadjacent the lateral edges thereof. the rear skid means comprising aplate which extends the full width of the frame.

13. Apparatus according to claim 1 wherein the front skid meanscomprises a pair of spaced skis on said forward frame section adjacentthe lateral edges thereof. the rear skid means comprising a plate whichextends the full width of the frame and which has an upwardly curvedfront end.

1. Apparatus for grooming a snow surface comprising an elongate framehaving forward and rearward ends and skid means adjacent each end tosupport the frame for sliding movement upon the snow surface, a bladestructure carried by said frame and extending transversely thereof, saidblade structure having a generally horizontal lower edge, a horizontalcompactor extending transversely of the frame and mounted thereonrearwardly of the blade structure, said compactor comprising a heavy,rigid, elongate member pivotally mounted on an axis transverse to saidframe, abutment means on said frame defining a limiting position forsaid compactor, said limiting position being spaced rearwardly anddownwardly of the pivotal axis such that the compactor is urged bygravity towards said limiting position but in operation may be displacedpivotally upwardly and rearwardly by the mass of snow to be compacted,and means for adjusting the height of said frame relative to saId skidmeans.
 1. Apparatus for grooming a snow surface comprising an elongateframe having forward and rearward ends and skid means adjacent each endto support the frame for sliding movement upon the snow surface, a bladestructure carried by said frame and extending transversely thereof, saidblade structure having a generally horizontal lower edge, a horizontalcompactor extending transversely of the frame and mounted thereonrearwardly of the blade structure, said compactor comprising a heavy,rigid, elongate member pivotally mounted on an axis transverse to saidframe, abutment means on said frame defining a limiting position forsaid compactor, said limiting position being spaced rearwardly anddownwardly of the pivotal axis such that the compactor is urged bygravity towards said limiting position but in operation may be displacedpivotally upwardly and rearwardly by the mass of snow to be compacted,and means for adjusting the height of said frame relative to saId skidmeans.
 2. Apparatus for grooming a snow surface comprising an elongateframe having forward and rearward ends and skid means adjacent each endto support the frame for sliding movement upon the snow surface, a bladestructure carried by said frame and extending transversely thereof, saidblade structure having a generally horizontal lower edge, a horizontalcompactor extending transversely of the frame and mounted thereonrearwardly of the blade structure, a deflector plate mounted on saidframe above and adjacent the rear of said blade structure, saiddeflector plate being of a length corresponding to that of the bladestructure and being downwardly inclined in the rearward direction sothat in operation it acts to deflect snow shaved by the blade structuredownwards into the path of the compactor, and means for adjusting theheight of said frame relative to said skid means.
 3. Apparatus accordingto claim 2 wherein the blade structure is downwardly and forwardlyinclined at an angle of approximately 45* to the vertical.
 4. Apparatusaccording to claim 2 wherein said front skid means comprises a pair ofspaced skis on the front portion of the frame adjacent the lateral edgesthereof the rear skid means comprising a plate which extends the fullwidth of the frame.
 5. Apparatus according to claim 2 wherein said bladestructure and said compactor extend over substantially the full width ofthe frame.
 6. Apparatus according to claim 2 further comprising asupport pivotally mounted on a transverse axis at the rear of said framesaid support carrying a pair of spaced, downwardly extending arms andthe lower end of each arm being pivoted to the rear skid means, andactuator means on said frame operative to pivot said support relative tosaid frame thereby to adjust the effective height of said frame relativeto said rear skid means.
 7. Apparatus according to claim 6 wherein saidactuator means comprises a fluid pressure operated piston and cylinderassembly connected at one end to said frame and at its opposite end ofsaid support at a location spaced from the pivotal axis of the latter.8. Apparatus according to claim 6 wherein said frame has a forwardsection upon which said front pair of skis is mounted and which isarticulated with respect to the remainder of said frame upon which saidblade and said compactor are mounted, said forward section of the framebeing adjustable in the vertical direction with respect to the remainderof said frame thereby to vary the effective height of the latter withrespect to the front skid means.
 9. Apparatus according to claim 8wherein said vertical adjustment is effected through a fluid pressureoperated piston and cylinder assembly connected between the forwardsection of said frame and the remainder of the frame.
 10. Apparatusaccording to claim 2 wherein at least the lateral end portions of saidblade structure are forwardly inclined with respect to said transversedirection.
 11. Apparatus according to claim 2 wherein said bladestructure comprises two blade sections which meet centrally of the frameand extend laterally therefrom at a slight forward inclination. 12.Apparatus according to claim 5 wherein the front skid means comprises apair of spaced skis on the front portion of the frame adjacent thelateral edges thereof, the rear skid means comprising a plate whichextends the full width of the frame.